Organic polymer compositions have numerous valuable properties which permit them to be used in the manufacture of a myriad of products. It has been observed however, that such polymers, under conditions of elevated temperatures and/or mechanical working, particularly in the presence of oxygen, undergo molecular degradation resulting in the deterioration of physical properties. Hydrolyzed oxyalkylated mercaptophenols have become very important as additives to polymer systems acting to retard and in some cases significantly arrest this degradation. U.S. Pat. No. 3,218,291 discloses examples to the uses of such mercaptophenols in retarding the degradation of synthetic rubber compositions, attesting to the growing importance of new and simpler methods for the preparation of high yield and high purity hydrolyzed oxyalkylated mercaptophenols.
Heretofore, the selective oxyalkylation of mercaptophenols in high yields and high purity has not been attainable. In a standard oxyalkylation of mercaptophenols, reaction at the mercapto function is always accompanied by some reacting of the hydroxy function because of the closeness in reactivity rates of the active hydrogen in the OH and SH functions.
It is an object of this invention to provide a process for the selective oxyalkylation of the mercapto function of a mercaptophenol. It is another object of this invention to provide a process wherein the mercapto function of a mercatophenol may be oxyalkylated in high yields and to a high degree of purity. Another object is to prepare new silylated derivatives of mercaptophenol compounds which are useful as intermediates for the preparation of oxyalkylated mercaptophenols. It is still another object of this invention to provide a simple process for the selective oxyalkylation of the mercapto function of a mercaptophenol. It is a further object to provide a new process for the preparation of hydroxy oxyalkylated mercaptophenols. These and other objects will become more apparent from the following discussion.